A review on progresses and performances in distillery stillage management

Air, Soil and Water Research

Chebude

et al. 2021

Self Cite

The objective of this study was to evaluate the treatment efficiency of a coupled stillage anaerobic digestion, which was performed in scoria-packed continuous reactors and following aerobic degradation. The optimum organic loading rate was determined for the continuous anaerobic digestion of a molasses ethanol distillery stillage with and without wet air feed pretreatment. The pretreatment of the molasses ethanol distillery stillage brought a significantly higher chemical oxygen demand removal in anaerobic digestion with an increased loading rate of 2000 mg/L d when compared with the raw stillage. The results also showed a complete removal of the biological oxygen demand following the coupling of anaerobic digestion with aerobic degradation. During the later stillage aerobic treatment, 68% of the chemical oxygen demand was removed within 8 hours of retention time. Despite the color, the removal of organics in stillage due to integrating wet air pretreatment, continuous anaerobic digestion, and aerobic degradation was successful. The pretreatment and hybrid technique also appears as a promising technique toward the sustainable management of stillage, thereby meeting discharge limit set for the ethanol industry by regulators.

Section: Introductionmentioning

confidence: 99%

Effect of Stillage Pretreatment During a Coupled Scoria-Supported Anaerobic Digestion Followed by Aerobic Degradation

Air, Soil and Water Research

Chebude

et al. 2021

Self Cite

“…However, the consumption of ethanol has got pros and cons regarding the water, energy and environment nexus worldwide [6][7][8] . This has led to the use of third generation biomass, distillery stillage, for energy generation, water reclamation and soil nutrient recovery thereby closing the gap in the economic cycle and ensure the sustainability of such sectors, especially in the developing countries [9][10][11] .…”

Section: Introductionmentioning

confidence: 99%

“…Few studies have been tested on continuous mode and the improved performance of AD was reported under xed lm digestion 19 . The xed lm AD used some media to pack the digesters with some synthetic medium which would help attach bio lm 10,23,24 .…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Organic Loading Rate and Chemical Oxygen Demand Removal: A Coupled Anaerobic-aerobic Treatment Approach for Molasses Distillery Stillage Treatment

Chebude

et al. 2020

Preprint

Self Cite

The objective of the current study is to determine the optimum organic loading rate for a continuous anaerobic digestion (AD) of an ethanol distillery stillage with and without of feed pretreatment. The AD has been performed in scoria packed continuous reactors. The pretreatment of the molasses ethanol distillery stillage brought a significantly better chemical oxygen demand (COD) removal with an increased loading rate to 2000 mg/L-d, when compared with the raw. The results obtained also showed a complete removal of the BOD, which was realized after applying the coupling of AD and aerobic treatments. During aerobic treatment, 68% of the organics were removed within eight hours of retention time. Despite the persistence of color, the removal of organics from integrating the wet air pretreatment, continuous AD and aerobic remediations appear to be promising technique towards the sustainable management of stillage thereby meeting discharge limits.

“…Stillage contains high COD, BOD, color-causing and refractory organics including the melanoidins, furfurals, phenolics, caramels, and odor-causing indole and skatole. These stillage contents are challenging the existing treatment technique, their discharge subsequently affecting the physical environment [1,2,3,4].…”

Section: Introductionmentioning

confidence: 99%

Efficient anaerobic digestion of a mild wet air pretreated molasses ethanol distillery stillage: A comparative approach

Sreekrishnan

et al. 2020

Heliyon

Self Cite

The effect of a mild, wet air pretreatment and the subsequent anaerobic digestion (AD) was examined on the recovery of a complex and toxic molasses ethanol distillery stillage. The biogas yield and organics removal due to pretreatment were compared with the raw stillage AD. The application of a scoria support in this industrial residue AD process stability was also assessed. Consequently, a statistically significant cumulative specific methane recovery difference (p-value ¼ 0.000) with an almost complete biological oxygen demand (BOD) removal and a significant chemical oxygen demand (COD) reduction, which were 100% and 92% respectively were achieved. Additionally, the biogas recovery rate was hastened due to pretreatment. The application of scoria, whose property has been instrumentally inspected, has helped stabilize the pH in the AD systems. In a comparative approach, this study suggests the energy benefit and an ecofriendly discharge of stillage by the ethanol industry towards sustainability.